Biology subjects

Vadboncoeur, E.

Publications and source records attributed to Vadboncoeur, E..

3 recordsLinked to original sources

bioRxiv2026

Defecation in preparation for ecdysis drives microplastic clearance in cricket nymphs

Plastic pollution is widespread in both terrestrial and marine environments, creating significant ecological concerns. Animals that occupy lower trophic levels, like many small insects, can ingest and retain plastics for extended periods before eliminating them. Ecdysis, or moulting, occurs in arthropods during development and facilitates growth, but its role in microplastic (MP) clearance, and whether it is impacted by plastics, are largely unexplored. We used the cricket Gryllodes sigillatus to examine how moulting influences MP clearance in a hemimetabolous species known to ingest and tolerate MPs throughout development. We tested two competing hypotheses of how moulting influences plastic clearance: (1) that moulting of the gut lining removes MPs, or (2) that cessation of feeding and purging frass before ecdysis occurs removes MPs. In doing so we also provide new evidence that cricket nymphs exhibit a cyclical (cosinor) pattern of frass production associated with ecdysis. MPs were eliminated from the crickets gut before ecdysis, driven by the cessation of feeding and cyclical frass production that clears the gut in preparation for ecdysis. We also observed that the timing of ecdysis and overall frass production remained unaffected by continuous MP ingestion, whereas switching between MP and non-MP diets caused modest changes in frass timing within an instar. Crickets are known to biofragment MPs into NPs, which, with gut-clearing, likely allows them to deposit plastic-laden frass rapidly and reduces the likelihood of upward trophic transfer by reducing plastic retention.

physiology↗

bioRxiv2025

Temperature outweighs diet in shaping developmental performance in two cricket species via growth delays and physiological limits

Understanding how chronic environmental stressors shape animal development is essential for predicting ecological responses and optimizing rearing systems. This perspective complements the use of short-term tolerance assays, which overlook the cumulative effects of sustained stress. Temperature and nutrition affect key life-history traits such as growth, development rate, and survival, which are closely tied to reproductive success and fitness. While both factors have been widely studied, their relative impacts arent clearly defined. We investigated how constant temperature (26- 41{degrees}C) and dietary protein-to-carbohydrate (P:C) ratio (0.15-2.18) influence development in two cricket species, Acheta domesticus and Gryllodes sigillatus. Growth trajectories were modelled using a unified-logistic equation to estimate asymptotic mass and relative growth rate. This approach captures the growth trajectory in a simplified and interpretable way, enabling comparisons across treatments. Asymptotic mass was combined with developmental rate and survival to calculate a composite metric of developmental performance. Developmental performance peaked at 35{degrees}C but fell at thermal extremes due to delayed development (in cold) or reduced mass and survival (in heat). Diet had more modest effects. Performance was stable across most P:C ratios, declining only at extreme imbalances. Notably, the performance cost of the most unbalanced diets was comparable to a 4-5{degrees}C shift from thermal optimum. Our results demonstrate that temperature, more than diet, drives variation in developmental performance during ad libitum feeding. This integrative framework provides a robust approach to quantify environmental sensitivity, define performance limits, and guide us toward the mechanisms underlying those limits and/or performance trade-offs. Summary statementTemperature more strongly influences growth trajectories and developmental performance than diet, due to delayed development and reduced survival at thermal extremes.

physiology↗

bioRxiv2024

Growth, development, and life history of a mass-reared edible insect, Gryllodes sigillatus (Orthoptera: Gryllidae)

Insects provide a potential source of sustainable, alternative protein that can help meet the protein demands of a growing population. Efficient farming of insects to meet this demand depends on an understanding of insect life history. Yet, detailed information and expertise about a single species are not always available for practitioners to make informed decisions about rearing practices or identify arising issues. The cricket (Gryllodes sigillatus) is commonly farmed for human consumption or animal feed, but few studies have characterized the life history of this species throughout ontogeny. Here, we describe the growth and development of G. sigillatus from hatch to adulthood and quantify reproductive traits relevant to mass-rearing and colony management, including egg development. This information provides foundation to start and manage a cricket colony and to conduct research on growth and performance. We highlight ways that a fundamental understanding of cricket biology can be informative for optimizing cricket growth, reducing variability in yield and informing future precision farming practices.

zoology↗